Looseleaf binder

ABSTRACT

A looseleaf binder formed integrally of synthetic resin having proper toughness and elasticity which comprises a cover plate provided in its internal surface with at least two or more posts, a base plate provided on its inner surface facing the inner surface of the cover plate with at least two or more sockets into which said posts are fitted disengageably and a flexible connecting means for joining the cover plate with the base plate symmetrically.

United States Patent Eitaro Miyamoto Tokyo, Japan 830,066

June 3, 1969 Oct. 12, 1971 King Jim Co., Ltd. Tokyo, Japan Sept. 26, 1968 Japan Inventor Appl. No. Filed Patented Assignee Priority LOOSELEAF BINDER 3 Claims, 8 Drawing Figs.

U.S. Cl 402/22, 402/8, 402/64 Int. Cl B42f 3/02, 1342f 13/30 Field of Search 402/19, 21 20, 22, 8, 64, 60, 61, 68; 281/1, 19, 37.5

[56] References Cited UNITED STATES PATENTS 2,891,554 6/1959 Foster 402/64 687,941 12/1901 Radford et a1. 402/22 828,974 8/1906 Schmidmer 402/8 1,670,396 5/1928 Wood 281/19 R 3,087,498 4/1963 Vogel 402/22 Primary Examiner-Robert W. Michell Assistant Examiner-R. P. Dyer Att0rney--Young & Thompson ABSTRACT: A looseleaf binder formed integrally of synthetic resin having proper toughness and elasticity which comprises a cover plate provided in its internal surface with at least two or more posts, a base plate provided on its inner surface facing the inner surface of the cover plate with at least two or more sockets into which said posts are fitted disengageably and a flexible connecting means for joining the cover plate with the base plate symmetrically.

PATENTEDnm 1 2 197i sum 1 OF 2 1 2.7 09

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ATTORNEY PATENTEU [JCT 12 I97! SHEET 2 OF 2 3, 612 709 FIG.7

INVENT OR Jan-d6 ATTORNEY LOOSELEAF BINDER BACKGROUND OF THE INVENTION This invention relates to an improvement in a looseleaf binder for sheets which comprises a cover plate provided with at least two or more posts and a base plate provided with at 7 SUMMARY OF THE INVENTION It is, therefore, a general object of the invention to obviate the above disadvantages and to provide a novel binder of simple construction free from any holding means which may be fabricated by mass production in a short time at reduced cost.

The principal object of the invention is to provide a new binder comprising a cover plate which is provided in its internal surface with at least two or more posts, a base plate which is provided in its internal surface facing with the internal surface of the cover plate with at least two or more sockets into which said posts are disengageably fitted and a flexible connecting means for joining the cover plate with the base plate symmetrically, wherein all elements are formed integrally of synthetic resin having proper toughness and elasticity.

Another object of the invention is to provide a new binder comprising a cover plate which is provided along its outer edge with at least two or more posts and along its opposite inner edge with two or more curved edges, a base plate which is provided along its outer edge with at least two or more sockets and along its opposite inner edge curved ridges that nest in said curved edges, and a flexible coupling means for connecting the cover plate with the base plate symmetrically, wherein all elements are fonned integrally of synthetic resin having proper toughness and elasticity.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will appear from the following description of the representative embodiments disclosed in the accompanying drawings in which the same reference numerals designate the same or similar parts throughout the drawings:

FIG. I is a perspective view of one embodiment of a binder according to the invention in opened relation;

FIG. 2 is a perspective view of the binder in closed relation;

FIG. 3 is a transverse sectional view taken along the line lIllII of FIG. 2;

FIG. 4 is a perspective view of the binder according to another embodiment in opened relation;

FIG. 5 is a perspective view of still another embodiment of the binder in opened relation;

FIG. 6 is a transverse sectional view in closed relation taken along the line VI-VI of FIG. 5;

FIG. 7 is a pictorial view showing the attachment of the binder shown in FIG. 5 to the file folder; and

FIG. 8 is a pictorial view similar to FIG. 7 but showing the attachment of two binders to the left side edge and the right upper edge of the file folder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 3, the binder according to the invention comprises a cover plate 1, a base plate 2 and flexible connecting means 3 and'all elements are integrally formed of synthetic resin having proper toughness and elasticity such as polypropylene.

On an inner surface of the cover plate 1 and near its outer edge are provided two posts 4 of substantially frustoconical shape. On an inner surface of the base plate 2 and near its outer edge are provided two sockets 5 having generally cylindrical inner surfaces and two apertures 6 for securing the base plate 2 to binder covers. The inside diameters of the sockets 5 are somewhat smaller than the outer diameters of the frustoconical posts 4 at their bases so that the posts 4 when fitted into the sockets 5 are kept in tight engagement with the interior walls of the sockets 5 owing to the friction of the synthetic resin. Accordingly, it will be appreciated that the binder according to the invention does not require any special holding means for-keeping the posts in engagement with the sockets.

The posts 4 may be provided on the base 2, while the sockets 5 may be provided on the cover plate I or they may be arranged alternately. Further, the numbers of the posts and the sockets may be increased optionally according to the purpose.

The flexible connecting means 3 for joining the cover plate 1 with the base plate 2 symmetrically comprises several con necting pieces 7 which when the cover plate I and the base plate 2 are to be closed are bent as shown in FIGS. 2 and 3, so that when the posts 4 are manually disengaged from the sockets 5 the cover plate 1 is lightly opened outwardly under the influence of the restoring force of the connecting pieces 7.

The connecting pieces 7 at their inner middle portion may be provided with grooves or they may be replaced by a continuous connecting band 8 provided with ridges and grooves as shown in FIG. 4 so that an increased restoring force is exerted by the connecting band 8 when the cover plate I is disengaged from the base plate 2 and, accordingly, the cover plate 1 is vigorously opened outwardly.

In FIGS. 5 and 6, the cover plate 1 at its inner edge and between the connecting pieces 7 is provided with several edges 9 which are somewhat curved inwardly.

On the other hand, the base plate 2 at its inner edge and between the connecting pieces 7 is provided with the ridges 10 of the same number as edges 9. Further, the top portions of the ridges 10 are rounded so that the rounded top portions come into tight contact with the curved portion of the edges 9. In operation, when the cover plate 1 is disengaged from the base plate 2, the edges 9 are bent about the rounded tops of the ridges 10 due to the resilience of the cover plate so that the cover plate I is vigorously opened outwardly on account of the leverage around the rounded top of the ridges 10.

The binder thus constructed according to the invention is usually attached to the file folder I l as shown in FIG. 7. However, it will be more convenient for the user when two binders are attached to the right upper edge and left side edge of the same file folder as shown in FIG. 8 so that the recorded papers at the right side may be flled seriatim to the left side of the file.

According to the invention, the binder does not require any intricate holding means for keeping the posts in engagement with the sockets and, accordingly, it may be operated with ease. Further, the binder as a whole is formed integrally of synthetic resin by mass production at reduced cost.

It should be understood that the invention is not limited to the particular embodiments shown and described herein, but that various changes and modifications may be made without departing from the scope of this novel concept as defined by the following claims.

What is claimed is:

l. A looseleaf binder of synthetic plastic material and comprising a base plate, a cover plate, a flexible member hingedly connecting the base plate to the cover plate, at least two connecting assemblies each comprising an interengaging post and socket, the post being mounted on one of the said plates and the socket on the other of said plates, the length of the socket being sufficient to receive a major part of the length of the post, the base plate and the cover plate having outer and inner edges, the flexible member extending between the inner edges, the posts and sockets being situated near the outer edges, the binder having an elongated ridge located along the inner edge of one of the plates and extending generally perpendicular to said plate, and an elongated curved edge extending along the inner edge of the other plate such that, when the posts and sockets are interengaged, the top of the ridge nests in said curved edge.

2. A binder according to claim 1, wherein at least two flexible members extend between the base plate and the cover 

1. A looseleaf binder of synthetic plastic material and comprising a base plate, a cover plate, a flexible member hingedly connecting the base plate to the cover plate, at least two connecting assemblies each comprising an interengaging post and socket, the post being mounted on one of the said plates and the socket on the other of said plates, the length of the socket being sufficient to receive a major part of the length of the post, the base plate and the cover plate having outer and inner edges, the flexible member extending between the inner edges, the posts and sockets being situated near the outer edges, the binder having an elongated ridge located along the inner edge of one of the plates and extending generally perpendicular to said plate, and an elongated curved edge extending along the inner edge of the other plate such that, when the posts and sockets are interengaged, the top of the ridge nests in said curved edge.
 2. A binder according to claim 1, wherein at least two flexible members extend between the base plate and the cover plate, and the ridge and the curved edge extend along said inner edges between the flexible members.
 3. A binder according to claim 1, wherein the top of the ridge is convex and the curved edge has a concave portion to receive said convex top. 